


Soul Fell

by XbugjuiceX



Category: Undertale (Video Game)
Genre: Alternate Universe - Soulmates, Alternate Universe - Underfell (Undertale), Good W. D. Gaster, Goopy W. D. Gaster, Multi, Other, Sans (Undertale) Has Issues, Soul Bond, Underfell Papyrus (Undertale), Underfell Sans (Undertale), Underfell Sans Needs a Hug (Undertale)
Language: English
Status: In-Progress
Published: 2020-12-22
Updated: 2020-12-22
Packaged: 2021-03-11 02:01:07
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,804
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28247316
Author URL: https://archiveofourown.org/users/XbugjuiceX/pseuds/XbugjuiceX
Summary: Magic has affected humans after being exposed from the barrier breaking. Soulmates exist, just not in the way humans always described them.. Soul sickness leads to (Y/n) finding themselves somewhere they never thought they would end up, but not with the people they have come to know and love..
Relationships: Sans (Undertale)/Original Character(s), Sans (Undertale)/Reader
Comments: 4
Kudos: 25





	Soul Fell

In the months following the emerge of monsters from the underground, there was an influx in magic as it circulated out with the monsters. Slowly, humans grew more in tune with the magic and their own souls. While there were no mages alive, this did end up with some surprising results. Such as the idea of soulmates. Two souls with such a similar song it indicated two people were extremely compatible. Everyone had at least one, but that wasn’t to say you weren’t compatible with other people.

Unfortunately, my soulmate was Sans. A skeleton monster who was short for being a monster but still inches above me. Lazy yet works several part-time jobs, loves anything involving space. We grew quite close when monsters first emerged, leading to my soul resonating with his. This was before I was aware of my own soul yet, but he should have been aware.  
I wasn’t the only human Sans got close to, however. He actually met another human who was a soulmate around the time I gained soul consciousness. They were a closer soulmate match, so of course they ended up together. This only resulted in me getting extremely ill, causing me to have Toriel come today to check me over.

“Weakness, exhaustion, a seemingly depressive state.. Dear may I please check your soul?” A short nod to her and a heavy pulling sensation on my chest led to my small Integrity soul bobbing in front of us both. The normally bright blue soul has dimmed since I’ve last seen it, and a new rather large crack has now graced its surface.

“Oh, well, that crack is new,” I informed her as she inspected the surface.

“My dear, it seems you’ve gotten soul sickness from breaking off an early soul resonation, that is where the crack has come from. There’s not much you can do but wait for your soul to recover. You will start producing excess magic as you try to heal your own soul, though I am unaware as of what this will result in for humans. Monsters expel extra magic with sweat or magic attacks, so please call me when new symptoms arise.” Soul back in place, Toriel gives me a few head pats before bringing me a glass of water and telling me to try and get more sleep. With this, she leaves me to my thoughts. By now I knew this was from Sans, but he has slowly started to stop hanging out. I haven’t seen him in at least a week now, and only see him when hanging out with our mutuals. Clearly he doesn’t want to be around me since getting closer to his other soulmate, and maybe that’s for the better. My soul was too attached already, he wouldn’t have been happy being around me anyways.

\------------------------------------------------------------------ 

As it turns out, excess human magic gets expelled similarly to vomit, but it just rushes out so there is no gagging or heaving. At least it isn’t very painful in comparison, but suddenly gushing blue magic is very startling, and always happens at the worst times, such as about to eat breakfast, getting groceries, or like right now, finally talking to Sans in the first time in weeks. It was to be expected, honestly. It has been happening more and more frequently, but Toriel said I shouldn’t be concerned just yet. Sans, however, looks extremely concerned. Tiny pin pricks staring as I pull out the napkins I have been carrying with me everywhere to wipe myself off.

“uh.. kid I might not know much about humans, but that can’t be natural. that’s not a normal color, right?” I could only laugh pitifully as tears slipped out. While not as painful as throwing up so often would be, it does sting.

“It’s normal now, I suppose. Nothing I can do about it now, anyways.” Sans glances around, face still showing concern and confusion. He starts to walk off, turning back to me quickly.

“i’m going to have toriel come look at this real quick, something isn’t right.” He alerts me before rushing off to pull the tall goat monster my way.

“My child, it still isn’t getting better?” This gets Sans’s attention fast, I guess he never knew I was sick to begin with. “I’d like to check on your soul to see if it has improved, if that is okay?”  
I gave my approval and watched as she tugged my soul out again. The small soul was still dimmer than normal, but there was a halo of blue coming off, indication of my excess magic. The crack however, was both better and worse. There was a deep blue filling in part of the crack, but it has started to splinter farther up. Glancing up in surprise and concern, Toriel seemed pretty alarmed herself. “Oh dear, even with your excess magic it seems to be healing too slow for it to properly fix itself.” I didn’t even need to look towards Sans to feel the excess magic rolling off of him now, an easy indicator that he was pissed.

“Hah, thanks Toriel, but you did already say there isn’t anything we can do, right?” I wasn’t looking at anyone anymore, instead looking off at the party, “We can only wait and see if it gets better, I’ll just stay home while I wait, maybe going out so much was what did it.” I quickly slipped past them and lost myself in the crowd of party goers. For once I felt thankful it was a pretty large party, mostly monsters I wasn’t personally acquainted with. Most monsters were super close underground, so it wasn’t surprising that they all came for the party. It didn’t take long to feel overwhelmed again with the number of strangers, so I weaved through to a vacant corner to try and catch myself. Being caught up in calming myself down, I didn’t see anyone approaching.

“Hey, you are (Y/n), right?” I glanced up at a brunette with olive eyes and a green dress staring at me. With my nod she continued, “I’m Sans’ soulmate, he talked about you sometimes so I figured it was you.” Ah of course, just the person I wanted to meet anytime soon. “He talked about how you were pretty clingy, and always wanted him to go hang out with you. Mostly I was curious on your side of the story, because his wasn’t very positive.” Oh that hurt, Sans talks badly about you? No wonder he never sends messages anymore or anything.

“What else does he say?” I asked that without stopping to think. I definitely do not want to know what else he bad mouths me about to his partner, but too late, I asked. I glanced around and flinched a bit as I saw Sans looking around franticly in the crowd. He is probably worried about his partner here talking to me.

“Well at first he would rant about you after visiting, so I asked him why he would even go if he was unhappy doing those things. Eventually he stopped but every now and then he would see you at events or out with friends and he would rant again. Stuff like you would always talk about yourself and were inconsiderate about his and the other feelings, he hated when you’d want to know more about the underground. He thought the others were being stupid still hanging out with you.” It was about this time that Sans noticed the two of us. He started speed walking over with wide eyes.  
“Well, that’s not how I thought it was like from my point of view, but I’m not about to question his experience, thank you for letting me know. I don’t want to upset him by being around his girlfriend though, so I’m going to head outside before he notices.” I give her a curt nod and quickly move into the crowd next to me to slip outside.

A glance behind me showed Sans anxiously talking to his girlfriend, I almost slipped out the door before he noticed, but his eye lights flit my way just for an instance. Damn, almost got away too. Outside, it was much less crowded, just a few people outside talking. My chest hurt, but at least I was out. I slipped around the building where I was alone and slid down against the wall. That definitely doesn’t feel like it helped my issue, but maybe that’s what I needed. The realization that all this pain and all the joy I used to have was for nothing kind of sucks though. A crunch and my head snapped up, locking eyed with a pair of familiar eye sockets. Ah, I guess he came to scold me for talking to her after all. It is hard to focus with the growing pain in my chest though. “Ah, somethings wrong,” I realize with a start, “This is definitely not okay, I feel like I’ve been shot.” His eyes shoot down to my hand gripping my shirt above the pain. “You probably hate me right now, but please, I really need help” His eye blazes blue as he reaches out, I let out a silent scream as it feels wrong, I know he is trying to take my soul out, but it feels like its being ripped out. Finally, it is out I try to focus on getting air as I slum back.

“ **s h i t.** ” I glanced up startled, just to see my soul cracking and splintering right in front of me. “hang on, kid, don’t fall down on me, keep your eyes open.”

“I’m not ready to go, but I don’t want to be here,” I muttered, feeling the magic trying to fix my soul stir up. The halo of blue blossoms again, showing my soul is trying to stay together. The world turns dark as I watch.

\------------------------------------------------ 

This could be what death is, but I don’t think so. This darkness, surrounding me from every side. I still feel heavy and broken, and I can see myself.

“Hello, child. I heard your soul cry out, I think I can help.”

I turn at the weird talk, eyes locking onto a globby individual. I could easily see his face and hands, however. His hands had holes in the middle, but as he moved them I heard his voice again, “The same but different, I think you will like it there.”

He then turned and ripped a hole into the darkness, a swirl of colors moving within the ripped gap, he gestured for me to enter. “A portal..? Uh, thank you, whoever you are,” I slowly clambered over, reaching over to the hole. With a single poke, the colors reached out and wrapped around me, and I was out again.

**Author's Note:**

> Gaster talk translated - “Hello, child. I heard your soul cry out, I think I can help.” & “The same but different, I think you will like it there.”


End file.
